North Carolina tests show vertical tillage increases wheat yields

What is in this article?:

• Vertical tillage refers to systems where soil disturbance is confined to soil movement mostly in the upward direction and/or confined to a slot or strip where the next crop rows are to be planted using strip-tillage implements or coulter-based implements that perform full width tillage.

• In the North Carolina tests, using a chisel plow on six dollar a bushel wheat added $15 per acre benefit. The 40-inch center DMI produced a $40 per acre benefit and the 20-inch center DMI produced a $45 per acre benefit.

Work at shallow depths

A number of growers in the Southeast have found DMI-type equipment handy for applying manure and fertilizers. These implements generally work at shallow soil depths and can be pulled across a field quickly enough to allow for treatment of a large number of acres in a short period of time.

In the Southeast there is a trend among growers with irrigation to grow corn behind corn and follow it with wheat to produce three crops in two years. While maximizing irrigation equipment, such practices are also maximizing soil traffic and are ideal for deep tillage applications.

The Upper Southeast typically undergoes a series of freeze and thaw situations in the winter, which tend to add structure to the soil. Last year the region had a record warm winter, which tends to leave soil with less structure.

The warm winter and spring also speeded up planting and reduced the cycle between compaction and rest for soils on many farms in the region.

All these factors should enhance the use of vertical tillage for growers planting in no-till or reduced tillage systems.

Love says many of the advantages of vertical tillage are too subtle to see by just watching a crop progress through the year.

“On the test we conducted on the Moore’s farm, we never saw any visible differences. We didn’t see it, but the yield data shows there was a significant yield increase by breaking the hard pan,” Love notes.

Vertical tillage isn’t so new to other parts of the U.S.

Brett Roberts, Illinois state agronomist, says it really isn’t a much different concept than anything farmers have used in the past.

“In a tremendous over-simplification, the vertical tillage tool is a hybrid of a disk and field cultivator. The concave disk is simply replaced with more flat disks and coulters. They don’t engage or throw much soil. They simply cut through the residue and only go a couple of inches deep,” Roberts explains.

He says vertical tillage was introduced in the Midwest about a decade ago. The idea was to avoid producing a hard layer of soil 3-4 inches below the surface. This is a scenario that occurs frequently on land that is in a long-term no-till system, he concludes.

In the Southeast, if soybean and wheat prices continue to drive acreage up, many growers will likely want to take a look at vertical tillage, especially on marginal land that is prone to hardpan buildups, Love says.